Sixteen adolescent cross-country skiers (6 males, 10 females) were assessed during a period of preparation carried out in the school year (period I) and during a period of training in the mountains before competition (period II). Body mass index (BMI), body composition (calculated from skinfolds) and dietary intake were ascertained over a 1 week period. The boys had the highest BMI and the lowest percentage of body fat when compared to controls and other athletic boys of comparable age. Their energy and protein intake (especially during period II) were also above the recommended dietary allowance (RDA) and above that of controls and other athletic boys of comparable age. The girls had a lower body fat percentage and BMI than untrained girls, and also elevated energy and protein intakes when compared to the RDA. The intake of energy, protein, fat, carbohydrate and micronutrients increased significantly during period II as compared to period I. An adequate energy balance was assumed as BMI and body fat did not change significantly during period II. Greater calcium intake during periods I and II, and a lower intake of iron during period I, when compared to the RDA, were observed in the girls. Thus, with the exception of micronutrients, which ought to be carefully monitored, the spontaneously regulated food intake was assumed to be adequate during changes in the intensity of training and climate in adolescent cross-country skiers.